Abstract: Disclosed is an expansion-sealed flood control gate, comprising a water board, a frame structure, two symmetrical constraint tracks, at least one encased expandable sealing tube, and a plurality of adapters. A U-shaped slot is formed between the two symmetrical constraint tracks for plugging in the water board. Each constraint track has a U-shaped expanding compression chamber connecting from one end to the other end to accommodate the tube inside. The adapters are connected with the open ends of the tube and fixed on the constraint tracks at the connected ends. Accordingly, there can be effectively repelled floods that the tube with the characteristics of active filling and uniform packing stress have the higher geometric tolerance, even if the slits between the water board, the constraint tracks and ground emerge the unexpected geometrical change, the encased expandable sealing tubes are ballooned to mend the slits.